I picked C and its pretty clear why its correct. I think what's confusing about B is that it would work if we assume that the fact that you received an apology means that you are owed one. Because saying "neither person is owed an apology unless both are" is equivalent to saying that if "one person is owed an apology, then both are". So if the physician is owed an apology, then so is the counselor.

The conclusion is not about the causal effect of the length of time on the value of training per se, but merely that long-term training is unwarranted. If the conclusion was making a broader argument that the value of training generally decreases with time, I think you would be right.

For instance, if you were to add E to the stimulus by adding a sentence after the second sentence that said "Furthermore, short-term relaxation training involves the teaching of a wider variety of anxiety-combating relaxation techniques than does long-term training." That wouldn't really hurt the validity of the conclusion in any way. I think it would just be irrelevant because it requires us to assume that a wider variety of relaxation techniques is in someway superior to a narrower variety.

I wondered this as well. I think this is correct but that the LSAT would just simply never give us an answer choice like this as it merely contradicts the premises. The premises say that we observe these differences in exit times, and the answer in that case would then say that we would not observe ("is not noticeably affected by") these differences in exit times.